Automatic doffing apparatus



Sept. 1942- F. A, DANIELS 2,296,339

'. AUTOMATIC DOFFINQ APPARATUS- Filed May 9, 1 9 41 S SheetS-Sheet 1 INVENTOR.

Frederickflflhurnaniels ATTORNEY ep 22. 942 F; A. DANIELS 2,296,339

AUTOMATIC DOFEING APPARATUS Filed May 9, 1941 3. Sheets-Sheet 2 INVENTOR.

I Frederick Arthur D aniel'a BY I - ATTORNEY Q Patented 1942 a r 2,296,339 I P AUTOMATIC DOFEING arrm'ros Frederick ma Daniels, Waynesboro, Va., as-

signor to ,E. I. du Pont de Nemours &,Cln1lfll7, Wilmington, Del., a corporation of Delaware Application my 9, 1941, Serial No. 392,804 8 Claims. l. 242-19) This invention. relates toapparatus for dofllng yarn. I More particularly it relates to apparatus for automatically transferring continuously produced yarn from a filled package to an empty yarn support without interrupting the continuity of the process, and without damaging and/or wasting yarn.

In many textile treating operations involving the collection of yarnin wound packages, it is usually the practice when a package is completed to momentarily interrupt the operation by stopping the spindle on which the filled yarn support, e. g. a bobbin, is carried. This stoppage must be long enough to permit the yarn to be cut, the full package removed, an empty yarn support inserted, and the yarn manually wound around it sufliciently to remain in place when the spindle is restarted. I l

Such a stoppage, however, cannot be tolerated in a continuous process, as for example, in the dry spinning of cellulose acetate yarn. To preserve the continuity of the process, means have heretoforebeen devised whereby the yarn can be temporarily transferred to a rotating waste roll while the package is being defied, following which the yarn is returned to the empty bobbin and the wrap removed from the waste roll. This operation is not satisfactory because (1) it contains an element of risk, particularly if the yarn is of ultra-heavy denier or if spun at high speed; (2) it is apt to cause considerable waste; and (3) it is usually necessary to dampen the face of the empty bobbin to cause the yarn to adhere to it, and this has a deleterious effect on the yarn itself since it tends to remove the finishes that have previously been applied and, under certain circumstances', causes nonuniformity of dyeing.

Various expedients have been proposed to overcome the latter defect, i.,e., to cause an empty bobbin to automatically engage the yarn so that dofllng can be carried out without the necessity of moistening the bobbin. One expedient has been'to provide on the end of the bobbin a spring appropriately shaped to engage the yarn and to securely grip it afterwards. Devices of this type have not proved entirely satisfactory except where comparatively fine denier yarn is involved.

This loss of tension effectively prevents adherence to the bobbin andjmakes automatic domng impossible. No satisfactory means for eliminating the element of.risk or for preventing considerable waste during dofllng in a continuous process have been disclosed heretofore.

' An object of this invention, therefore, is to provide apparatus for automatically transferring yarn from a full package to an empty yarn support without stoppage, and without danger of personal injury to the operator.

A further object resides in the provision of apparatus for automatically transferring yarn in a continuous process without waste of, or damage to, theyarn.

A still further object is to provide an automatic dofllng device particularly effective in the handling of ultra-heavy denier yarn.

Anotherobject is to furnish a yarn support provided with improved .meansv for engaging the yarn.

These and other objects will more clearly appear hereinafter.

I have found that both parallel multiefilament yarns of any commercial size will readily cling to wire card cloth of the type used in combing machines for removing tangles and parallelizing individual fibers in the manufacture of cotton and other types of batting.

In the case of very heavy multi-filament rope (which may bev collected for subsequent cutting into staple), as for example, a continuous-filament rope of 30,000 denier, a pick-up spring or,

as is also used, a tapered notch on the end of the bobbin portion of the filaments,

is not satisfactory since it grips only a leaving the remainder to slip out of engagement and to lose tension.

1 from one face of'the belt.

If the wire card cloth moves in the same direction and at substantially the same velocity as the yarn, as for example, when a feed roll is covered with wire card cloth, thev yam clings so readily that there appears to be no loss of tension.

Wire card cloth usually consists of a belt pierced with sharp pointed, closelyspaced metal staples r i in such a way that the points or teeth all project The ends of the teeth are usually bent to a definite angle to improve their tendency to engage and parallellize tangled fibers. The use of such a material on a rotating cylinder in its usual manner, wherein the teeth are bent against the direction of rotation would probably entail a sufficiently serious operating 'hazard 'toprohibit its use in any application wherein an operator's hand could contact it while in motion. I have found further, however, that surprisingly enough, the direction of inclination of the teeth has relatively little bearing on the eifectiveness with which they will seize a parallelfilament rope. Parallel-filament ropes as large as 32,400 denier, for example, can be positively gripped while in motion without any apparent wet and dry ropes of" can be picked up by th other.

loss of tension, irrespective of the angle of inclination of the teeth.

These findings have made possible the development of the apparatus of my invention, a preferred form of which is hereinafter described in connection with the drawings-wherein:

Fig. 1 is a front elevation of the apparatus;

Fig 2 is an end view with parts broken away to show the means of mounting the bobbins and means for shiftingv the yarn;

Fig. 3 in a detail view of the portions of the bobbins and of the dofllng wheel incorporating the yarn engaging means of this invention; and

Fig. 4 is an end view on the line 4-4 of Fig. 3.

Referring to Figs. 1 and 2, feed roll I, shifter fork 2, and self-threading traverse guides 3 and 4, all of conventional design, are provided to conduct the yarn to the yarn collection means which comprises a drive roll 5, positively driven about a fixed axis, andtubular bobbins 6 and I removably mounted and freely rotatable on spindles 8 and 9, respectively, which project from swingarms Ill and II, respectively. The swing-arms are independently mounted in such manner that the bobbins can be moved into contact with, or away from, drive roll 5 which is common to both bobbins, and still maintain axial parallelism with the drive roll.

The adjacent ends of each bobbin carry a narrow band l2 and I3 of radially projecting pins or teeth (Fig. 3) which form substantially the same curved surface as formed by projecting or extending the curved surface of the bobbin, and which therefore move at substantially the same velocity as the cylindrical surface of the empty bobbin. Conveniently these bands are made from conventional card cloth. Scored in the bobbins alongside the outer side of each of these bands is a shallow groove 24 and 25 to permit a knife to be safely held against the rotating bobbin should it become necessary to remove loose ends of the yarn. a

Suflicientspace is left between the adjacent ends of the bobbins to permit an auxiliary swingarm H to be lowered into place against the central part of drive roll 5 when dofling. This auxiliary swing-arm has a spindle l5 projecting from each side, each projection carrying a dofling wheel consisting of a narrow band I6 and I! of radially extending pins or teeth attached respectively to a driving disc l8 and I9. The doffing wheels rotate on ball bearings 20 and 2|, and since the outside diameter of the bands It and I1 is substantially the same as that of the driving discs, the teeth move practically at yarn speed when the discs are brought into contact with the driv roll.

The auxiliary swing-arm contains a removable razor-edged blade 22 (see Fig. 4) equipped with suitably shaped guides and solocated that it will sever the yarn when it is gripped simultaneously by wire cards It and I! and by their rotation carried against the cutting edge the blade.

As previously stated, the reciprocating traverse guides 3 and 4 are self-threading, being so shaped that they run under the yarn and automatically steer it into the guide slot, but it is necessary to lift the yarn from on traverse guide before-it This is accomplished by lifter bar 23 which normally lies just below the path of the yarn and is mechanically connected by cam 26 and bell-crank lever 21 to the shifter mechanism so that when shifter fork 2 is moved by lever 2 to guide the yarn from one bobbin to the other, th lifter bar imme- 7 diately rises and lifts the yarn out of the, traverse guide slot. The yarn is held out of engagement until the shifter bar has moved it almost in line with the other bobbin. Completing the movement of the shifter fork 2 causes the lifter bar to drop and the yarn then returns to its normal path and is automatically picked up by the traverse guide as it passes beneath it.

The operation of a typical transfer cycle is as follows. Shifter fork 2 is assumed to be in the position shown on Fig. 1 with the yarn passing through traverse guide 3 and being wound on bobbin 6 carried by the swing-arm Hi. When this bobbin fills and it becomes necessary to transfer the rope to empty bobbin 1, swing-arm H is lowered into place until the bobbin is in contact with and rotating at the same surface speed as driv roll 5. Simultaneously, auxiliary swing-arm I4 is also lowered and sufficient pressure applied to cause driving discs I8 and I9 to acquire the same velocity as the face of the drive roll. Lever 2' is then rapidly pushed over to its opposite position and in doing so causes shifter fork 2 to line up with the center of empty bobbin 1. During this operation a cam 26 actuates lifter bar 23 and causes it to lift the yarn out of the guide slot of traverse guide 3 andto hold it out of engagement with both traverse guides until it is almost in line with bobbin I, at which point lifter bar 23 begins to drop. When the movement of lever 2 is complete, the yarn falls to its normal path with relation o bobbin 1 and is then in position to be picked up by self-threading traverse guide 4.

During this procedure, the yarn has moved over the end of bobbin 6 and has become gripped successively by the teeth of bands l2 l6, l1, and I3. The angularity of the yarn path with respect to bobbin 1 (caused by the new location of shifter fork 2) causes the yarn to move to the center of bobbin 1 and, since at thi point it is lowered by shifter 23, is automatically picked up by the reciprocating traverse guide 4 and continues to wind up on bobbin 1.

The yarn bridging the gap between l6 and I! has been carried by their rotation into contact with blade 22 and consequently the full package on bobbin 6 continues to rotate but with its severed end of the rope gripped by the teeth of bands l2 and I6. Bobbin 'l is now rotating but with its severed end of the rope held by the teeth of rotating bands l1 and [3. A sharp knife is now held in the guide groove 24 at the end of bobbin 6 and the rope severed between bands l2 and IE to permit swing-arm I0 and full package to be swung away from the roll and the package to be removed. The knife is then held in the guide groove 25 in the end of bobbin 1 and the rope further severed between wire cards l1 and I3. Bobbin l is thus in a condition to permit it to continue to build up to full size, and the cycle is completed by swinging out arm l4, removing the waste yarn entangled onwire cards 16 and I1, examining the condition of blade 22, removing the full package, and inserting an empty bobbin on swing-arm spindle 8 in readiness for the next transfer operation.

It is understood, of course, that the above description is by way of illustration and is not limitative, for it is obvious that the invention is subject to a wide variation from the preferred specific embodiment. Thus in place of the swingarm type of bobbin holder, other types of bobbin holders intended for use with a constant speed surface drive, may be used, as for example, slotted guides engaging the ends of a spindle passing through the bobbin in such a manner that the bobbin can rise or move along the guides as the package builds up in size. Also this invention may be used for transferring from a package, which is not being wound at a constant yam speed providing the toothed bands are rotating at the peripheral speed of the empty bobbin. Likewise, obvious mechanical equivalents could be substituted for the specific bobbin, drive roll, shifter arm, and thread guide and other structures, herein disclosed, and modification particularly suited to the handling 'of yarn deniers.

within a restricted range, either extremely high or extremely low, .could also be made without departing from either the spirit or terms of my invention.

It is, however, essential that the rope be delivered to the bobbin at approximately .its line of contact with the drive roll in the manner usually known as "reverse rotation." Unless the rope is fed to the bobbin in this fashion, it is usually not possible to transfer it from a full package to an adjacent empty core since it loses tension and in consequence tends to-become entangle in the yarn traversemechanism. i

I claim:

1. A device for continuously "winding 'textile filaments, yarns, and threads comprising two freely rotatable yarn supports, a positivelydriven drive roll, means to positionsaid yarn supports in horizontal alignment against the cylindrical surface of said rolls, two horizontally aligned and freely rotatable dofiing wheels positioned between the adjacent ends of said yarn.

supports, said yam supports being provided at their adjacent ends with a band comprised of a plurality of radially projecting pins adapted to engage the'yarn, said dotting wheels each being provided with a band of pins substantially identical with those of the yarn supports, and means positioned between the dofiing wheels to sever yarn therebetween.

2. A device for continuously winding textile filaments, yarns, and threads comprising two freely rotatable bobbins, a positively-driven drive roll, means to bring said bobbins into driving contact with the drive roll in axial alignment, two freely rotatable dofiing wheels mounted to contact said drive roll between the adjacent ends of the bobbins and in axial alignment with said bobbins, said domng wheels and the adjacent ends of said bobbins each being provided with a band comprising a plurality of radially extending pins adapted to engage the yarn without substantially modifying its speed of travel, and

means mounted between'the doffing wheels for severing yarn.

3. A device for continuously winding textile filaments, yarns, and threads comprising two freely rotatable bobbins, a positively-driven drive yarn into the bobbin at substantially its lineof contact with the drive roll.

4. A device for continuously winding textile filaments, yarns, and threads comprising two freely rotatable bobbins, a positively-driven drive roll, means to bring said bobbins into driving contact with the drive roll in axial alignment, two freely rotatable dotting wheels mounted to contact said drive roll between the adjacent ends of the bobbins and in axial alignment with said bobbins, said dofiing wheels and the adjacent ends of said bobbins each being provided with a band comprising a plurality of radially extending pins adapted to engage the yarn without substantially modifying its speed of travel, means mounted between the domng wheels for severing yarn, traversing thread guide means associated with each bobbin and positioned to feed yarn into the bobbin at substantially its line of contact with the drive roll, and means for shifting the yarn from one thread guide to the other.

5. A device for continuously winding yam comprising two freely rotatable yarn supports dis posed end to end and in spaced relationship, a drive roll, means for independently positioning said yarn supports in driving contact with said drive roll, the line of contact of one support with the roll being a straight line extension of the line of contact of the other support with the roll, each of said yarn supports being provided with a plurality of radially extending pins disposed in a band closely adjacent the contiguous ends of said supports. the outer extremities of said pins being in substantially the same plane with the outer surface of said yarn supports, two axially aligned freely rotatable dofiing wheels each provided with a band of radially projecting pins, means to drive said dofling wheel at substantially the peripheral velocity of the drive roll, and means to bring said dofllng wheel into contact with the drive roll between the ends of said yarn supports and on substantially the line of contact of the drive roll and the yarn supports, means to sever the yarn located between said dofling wheels, and reciprocable thread guides associated with each yarn support and positioned to feed yarn on the sup ports at substantially the line of contact between J the drive roll and yarn support.

6. In apparatus for continuously winding yarnwherein dofling wheels are provided for transferring the continuously traveling yarn from a filled yarn support to an empty yarn support, the improvement which comprises providing the dofiing wheels and one end of each yam support with yarn pick-up means comprising a narrow band of radially projecting pins the outer extremities of which lie in substantially the curved plane of the dofllng wheel, and yarn support surfaces.

roll, means to bring said bobbins into driving project out radially from the axis of the dofiing 7. In apparatus for continuously collecting yarn in wound packages wherein freely rotatable bobbins are driven by a positively-driven drive roll and doiilng wheels also driven by the drive roll'are used to transfer continuously rurming yarns from the filled bobbin to the empty bobbin, the improvement which comprises providing the dofiing wheels and the end of the bobbin which initially engages the yarn, with a yam pick-up device comprising a plurality of pins which are confined within a narrow circumferential band about the dofling wheels and bobbin, and which wheels and bobbins to such an extent that their extremities travel, at substantially the same linear speed as does a point on the surface of the drive roll.

8. A bobbin for yarn comprising a cylindrical body member provided with a portion of reduced diameter at one end, means to mount said body member freely rotatable on a spindle, a plurality of pins radiallyprojecting from the portion of reduceddiameter to substantially the maximum diameter of the cylindrical body member and a circumferential groove immediately adjacent the o'uterendof said portion of reduced diameter, said groove being shaped to receive the cutting edge of a knife.

FREDERICK A. DANIELS. 

